The Earth's climate is always warming and cooling. Like the weather, it is a dynamic system.

The impact of these changes on our lives is significant and important. But also significant and important would be the cost of measures aimed at reducing human greenhouse gas emissions. It is important, therefore, to get the science right before raising taxes or adopting expensive government mandates.

In this brief video, two leading climate scientists -- Dr. David Legates and Dr. Willie Soon -- explain why the current warming trend is probably natural -- the result of solar cycles -- and therefore is unstoppable. They point to evidence in Greenland -- which was much warmer at the height of the last natural warming cycle than it is today -- and elsewhere. Many other scientists support their views.

This video is short, fast-moving, educational, and yet scientifically accurate. Share it with your family and friends, teachers, and civic or business leaders you might know. Let them know global warming is natural... and unstoppable.

The Idea Channel has produced this video, a not-for-profit educational corporation.www.ideachannel.com